x1, y1, x2, y2 = map(float, input().split())
x = abs(x2 - x1)
y = abs(y2 - y1)
r = (x**2 + y**2)**(1/2)
print(r)
 x1, y1, x2, y2 = map(float, input().split()) x1 map(float, input().split()) map float input().split() ().split () input split y1 x2 y2 x = abs(x2 - x1) x abs(x2 - x1) abs x2 - x1 x2 x1 y = abs(y2 - y1) y abs(y2 - y1) abs y2 - y1 y2 y1 r = (x**2 + y**2)**(1/2) r (x**2 + y**2)**(1/2) x**2 + y**2 x**2 x 2 y**2 y 2 1/2 1 2 print(r) print r x2, y2 = map(float, input().split()) map(float, input().split()) x2 y = abs(y2 - y1) abs(y2 - y1) y y2 = map(float, input().split()) map(float, input().split()) y2 x = abs(x2 - x1) abs(x2 - x1) x y1, x2, y2 = map(float, input().split()) map(float, input().split()) y1 x1, y1, x2, y2 = map(float, input().split()) map(float, input().split()) x1 r = (x**2 + y**2)**(1/2) (x**2 + y**2)**(1/2) r
x1, y1, x2, y2 = map(float, input().split())
x = abs(x2 - x1)
y = abs(y2 - y1)
r = (x**2 + y**2)**(1/2)
print(r)

